Maetufacturietg tube-sheets fob



IIIITED S WILLIAM S.

i. armati HUDSON, OF PA'IEPLSON, NIfHV JERSEY.

MANUFACTURING TUBE-SHEETS FOR BOILERS.

To all whom t may concern:

Be it known that I, IVILLIAM S. IIUDsoN, of Paterson, in the county ofPassaic and State of New Jersey, have invented a new and improved modeof producing two or more grades of uniform thickness in a sheet of metalsuch as is required for tube sheets for boilers of locomotives and forother pui'- poses; and I do hereby declare that the following is a fulland exact description of the same, reference being had to theaccompanying drawings,

By the term two or more grades of uniform thickness in a sheet of metalI mean to describe metal sheets of such a form that one part of a sheetis uniformly of one thickness and another part is uniformly of anotherand different thickness.

The tube sheets `of locomotive and other similar boilers require to bethick at their upper parts where the tubes are united thereto and to bethin at their lower parts. Heretofore such form has only been producedby haimnering down the metal to produce the thin part while only thethick part could be rolled into the proper forni. The process ofhammering is expensive and is liable for obvious reasons to produce aless perfect sheetthan does the process of rolling which latter isemployed in my invention in the manner which will now be described.

Figure 1 represents a tube sheet of the character which my invention isdesigned to produce, it differing in no wise from others before knownexcept that it is produced by rolling, so as to possess the properthickness in all its parts, and at the same time to have the quality ofcheapness and uniformity due to the rolling in coiitiadistinction toliaiiiiiiei'ing. Fig. 2 represents two sheets A and B of common oruniformly thick sheet metal. I apply them together in the mannerrepresented and pass them in that condition through the rolls for thepurpose of uniformly reducing the thickness of a portion of each withoutaffecting the remainder. F G represents the same sheets reduced to thecondition desired, A being the'thinned part of A, and B being` thethinned part of B. Figs. 3, 4, and represent tlie rollers C, D, with thesheets A, B, in the act of being passed through or of changing from onecondition to the other.

rIhe thicknessv of both parts of the sheets A, B, is in practice muchless (in comparison with the diameter of the rolls C D) than isrepresented in the drawings, the ratio being such that the bite of therolls, C D, will readily seize and not repel the superposed plate A whenin the position shown in Fig. Q.

To enable others skilled in the art to make and use my invention I willniinutely describe it as follows.

The sheets A, B, are first rolled iii the ordinary manner until thethickness proper for the thick portion obtains throughout the entiresheet. Two such sheets are now applied together in the manner indicatedand again passed through the rolls. In this latter operation the actionof the rolls reduces only that Vpart of each which is opposite to theother, to wit: the parts A and B in Figs. 5 and G, leaving theprojecting parts A 'and B, or the parts not thus lapped upon each other,unreduced and entirely unaffected by the operation.

I am aware that it has been heretofore proposed to give au irregularforni to a bar or sheet of iron by placing with it a counterpart of theform required, and passing both together through the rolls, but in suchcase the counterpart or mold is not compressed, it serving only to giveform to the article. My invention differs from the above in theimportant particular that I place two similar pieces together, havingboth at the same degree of plasticity, and each serving as the mold forthe other, both being reduced equally, and the result being theproduction of two sheets by the same operation which previously producedbut one. Beyond the obvious economy resulting from this doubleproduction there is another advantage in my method over that abovedescribed, in the fact that as both pieces are of equal plasticity,botli are elongated together, and therefore there is no slipping of oneupon the other and thus iinpairing the surface, or bending of either orboth, as there is where one cold and one hot plate ai'e used together.

My invention is applicable to the manufacture of iron or copper or othermetal sheets, and to the working thereof at any degree of temperature inwhich the metal can be prei eily reduced by rolling.

Ilaving now fully described my invention what I claim as new therein anddesire to secure by Letters latent is- The within described method oflnfoducing a rolled metal sheet one part of which is uniformly of onethickness and another aart In testimony whereof I have hereunto set ofwhich is uniformly of another und di ermy name in the presence of tWosubscribing 10 ent thickness; that is to say, first rolling theWitnesses.

entire sheet to the thickness required for the thick portion, andafterward rolling tWo WVM' S' HUDSON' sheets with the portions requiredto be thin- `Witnessesz ner superposed one upon the, other Substan-ROBERT S. HUGHES,

tiully as herein Set forth. JAMES C. CHRISTIE.

